This invention relates to a fluid control valve. More particularly but not exclusively, the invention relates to a fluid control valve suitable for use in medical procedures such as arteriography and angioplasty.
Various medical procedures involve the introduction of fluids into the body of a patient using a catheter. When a series of different fluids are to be administered, it is necessary to completely flush one fluid from the catheter before the next fluid is administered. For example, during arteriography or angioplasty, the lines must be flushed with saline before and after the addition of contrast media. When this is done, it is important that no contaminant be permitted to pass to the patient along with the fluid, since the presence of contaminant creates the risk of injury, infection or an embolism, with possibly fatal consequences. Furthermore, before the fluids can be introduced, it may be necessary to purge the injection line of air. After the air has been purged it is important to prevent the reintroduction of air. Therefore, it is necessary to be able to selectively connect the catheter to any one of a number of devices, such as fluid reservoirs for contrast dye or saline solution, exhaust ports, and pressure ganges without allowing air or contaminants to enter the catheter. The most commonly used apparatus for connecting a catheter with other equipment is a manifold which consists of a plurality of three-way stopcocks connected in series. One of the stopcocks is connected to the catheter, while the other stopcocks are connected to other pieces of equipment. By selectively opening and closing the stopcocks, the catheter can be made to communicate with any one of the pieces of equipment.
A conventional stopcock manifold has a number of problems which make it not only difficult but potentially dangerous to use. Since a plurality of stopcocks must be manipulated to achieve a desired flow path to the catheter, it takes a considerable degree of training to learn how to properly set all the stopcocks. Furthermore, as it is not immediately evident from looking at the manifold which way fluid is flowing, it is quite easy to make an improper connection. This could result in a fluid being mistakenly passed into a patient's body via the catheter, or in a high-pressure fluid being mistakenly applied to a pressure transducer having a low rated pressure, causing damage to the transducer.
Furthermore, a stopcock manifold includes a large number of moving parts, so it is expensive to manufacture. In addition, since the manifold usually has at least three stopcocks, there is a tendency to make each stopcock as small as possible in order to minimize the size of the manifold. The resulting stopcocks have very small handles which are difficult to grasp and manipulate.